The present invention relates to a staple extractor, and more particularly to a manually operated extractor for surgical staples.
Surgeons are turning more and more frequently to the use of surgical staples, rather than conventional thread sutures, for closing wounds or incisions in the skin of a patient, because the stapling operation is often simpler. More important, however, is the fact that stapling is much faster than conventional thread suturing. Thus, particularly in those instances where a considerable amount of suturing is required, the length of time for the suturing operation and the length of time the patient must be maintained under anesthesia are greatly reduced when surgical staples are used.
Typical surgical staples are illustrated in U.S. Pat. Nos. 3,643,851 and 3,837,555. A staple of this type initially has an elongated crown terminating in a downwardly depending portion whose free ends are provided with downwardly and outwardly sloping cuts, forming points. During the forming and implanting of such a staple in the skin of a patient, end portions of the elongated crown are bent downwardly. This forms a staple with a narrower crown and L-shaped legs, the pointed ends of which are opposed.
The types of staple described above may be removed from the skin of a patient by bending the staple crown into a U-shaped configuration. This will cause the L-shaped legs of the staple to shift upwardly and outwardly so that they may be lifted from the patient's skin.
The prior art has proposed manual extractors for bending the crown of surgical staples and lifting the staple from the patient's skin. Typically, a prior art extractor comprises a pliers-like tool having first and second handle means pivoted together and formed of sheet metal. The first handle means terminates in a pair of anvils in parallel spaced relationship. The anvils are provided at their rearward ends with notches so that, when the anvils are slipped under the crown portion of a surgical staple, the crown will be received in the notches.
The second handle of the extractor generally is provided with a relatively thick, two-ply, blade-like forward end substantially as long or longer than the anvils. The anvils have projections extending towards one another to guide the blade-like forward end between them. When the handle elements of the extractor are in their open position, this blade lies above the anvils and the notches therein. As the handle elements are shifted to their closed position, the blade element passes between the anvils and the notches therein making the above described U-shaped bend in the staple crown located in the notches.
It is clear that when the anvils are slipped beneath the crown of a staple, they will rub against traumatized areas of the skin, causing pain to the patient. Since the blade is as long or longer than the anvils, it partially obscures the anvils, making their proper insertion under the staple crown and location of the staple crown in the anvil notches more difficult.
Another prior art manually operated surgical staple extractor has been proposed in U.S. Pat. No. 4,026,520 which is in the form of a pliers-like tool having first and second handle elements pivotally joined together near their forward ends. These handle elements are manually shiftable between open and closed positions and may be biased to their open position.
The first handle element is bifurcated at its forward end, the bifurcations terminating in a pair of elongated anvils in parallel spaced relationship. The forward ends of the anvils are angled toward each other with the front-most tips being contiguous or nearly so. At their rearward ends, the anvils are provided with aligned notches to receive the crown of a staple. The bifurcations of the first handle element provide a steep upwardly and rearwardly sloping surface adjacent each of the anvil notches to assist in and assure the location of a staple crown in the notches.
A thin blade means is located between the bifurcations of the first handle element and is operatively connected to the forward end of the second anvil element. The blade means has a nose portion shorter than the anvils and a lower edge adapted to produce a U-shaped bend in the crown of a staple located in the anvil notches. The blade nose portion is shiftable by the second handle element between a first position (when the handle elements are in their open position) wherein the lower edge of the nose lies above the anvils and the notches therein and a second position (when the handle elements are in their closed position) wherein the nose lies between the anvils with the lower edge of the nose located below the anvils.
The problem with this latter prior art construction is that it, also, does not overcome all of the earlier disadvantages.
For example, the front end portion of the anvils must be inclined and positioned with considerable precision in order to perform their intended purpose, i.e. to guide the blade as do the transverse anvil projections of the art prior thereto. The extractor must be urged to open position by a biasing means whose presence complicates the construction and may become dislocated, tending to jam the extractor. Also, the more or less planar finger-engaging portions of this tool do not offer very reliable assurance against slippage of the surgeon's fingers which may lead to slippage of the extractor, pulling on the staple and pain to the patient.